检索结果-南通市图书馆

Anticorrosion behavior of conversion coatings obtained from unbuffered cerium salts solutions on AA6061-T6

在线全文

学校读者我要写书评

暂无评论

Journal of Rare Earths 2011年第10期29卷 961-968页

作者： KIYOTA sayuri VALDEZ Benjamin sTOYTCHEVA Margarita ZLATEV Roumen BAsTIDAs jose maria Engineering Institute of UABC B.Juárez Blvd.and Normal St.21280 MexicaliB.C.Mexico CENIM-National Centre for Metallurgical Research CSIC8Gregorio del Amo Ave.28040 MadridSpain

The anticorrosive properties of cerium based conversion coatings deposited on AA6061-T6 alloy by immersion in tmbuffercd cerium chloride and cerium nitrate solutions in the presence of hydrogen peroxide were investigated and characterized by potentiodynamic po- larization （PDP） and electrochemical impedance spectroscopy （EIs） in 0.5 mol/L NaCl aqueous solution. The microstructure and chemical composition of the protective films were examined by scanning electron microscopy （sEM） and energy dispersive X-ray spectroscopy （EDs）. It was found that the best corrosion protection was afforded by the samples treated during 600 s in cerium chloride solution at pH values ~5.5-4, showing higher amounts of cerium and polarization resistance values greater than 10 f~ m2. Moreover, an ennoblement of the corro- sion potential and decreasing of the cathodic and anodic currents were obtained compared with the cerium nitrate solutions application. This behavior was attributed to the influence of the deposition parameters such as type of the salt anion, i.e., chelating effect and chaotropic characteristics, pH fluctuations in the conversion solution and deposition time.

关键词： cerium based conversion coatings EIs PDP anticorrosion properties rare earths

systemic epigallocatechin gallate protects against retinal degeneration and hepatic oxidative stress in the P23H-1 rat

在线全文

学校读者我要写书评

暂无评论

Neural Regeneration Research 2022年第3期17卷 625-631页

作者： Lorena Perdices Lorena Fuentes-Broto Francisco segura Ana Cavero Elvira Orduna-Hospital Gema Insa-sánchez Ana Isabel sánchez-Cano Laura Fernández-sánchez Nicolás Cuenca Isabel Pinilla Aragón Institute for Health Research(IIs Aragón) ZaragozaSpain Pharmacology Physiology&Legal and Forensic MedicineUniversity of ZaragozaZaragozaSpain Department of Applied Physics University of ZaragozaZaragozaSpain Health sciences Faculty San Jorge UniversityVillanueva de GállegoSpain Department of Ophthalmology Miguel Servet University HospitalZaragozaSpain Department of Physiology Genetics and MicrobiologyUniversity of AlicanteAlicanteSpain Department of surgery Gynecology and ObstetricsUniversity of ZaragozaZaragozaSpain/Department of OphthalmologyLozano Blesa University HospitalZaragozaSpain

Retinitis pigmentosa(RP) is a group of inherited retinal disorders that lead to photoreceptor *** has been reported to be related to oxidative stress,autophagy,and inflammation.(-)-Epigallocatechin gallate(EGCG),the most abundant catechin-based flavonoid in green tea leaves,has significant antioxidant,anti-carcinogenic,antimicrobial,and neuroprotective ***,given its low molecular weight and hydrophilic properties,can cross the blood-retinal barrier and is able to reach different ocular tissues such as the lens,cornea,and *** has been shown to provide retinal protection against ischemia;sodium nitroprusside-,N-methyl-D-aspartate-,lipopolysaccharide-,light-,sodium iodate-,or H2 O2-induced damage and diabetic *** suggests that systemic EGCG administration has the potential to protect against retinal degenerative or neurodegenerative diseases such as *** aim of this work was to investigate whether EGCG can protect against RP progression in the animal P23 H line 1,the model of *** P23 H rats were crossed with pigmented Long Evans rats to produce offspring exhibiting the clinical features of *** P23 H rats were treated via intraperitoneal injection with saline or EGCG at a dose of 25 mg/kg every week from P100 to P160 and then compared to wild-type Long Evans *** treated with EGCG showed better visual and retinal electrical function with increased contrast sensitivity and b-wave values compared with those observed in P23 H rats treated with *** reduced lipid peroxidation and increased total antioxidant capacity and catalase and superoxide dismutase *** differences were observed in visual acuity,nitrate levels,nitrite levels or glutathione s-transferase *** conclusion,EGCG not only reduced the loss of visual function in P23 H rats but also improved the levels of antioxidant enzymes and reduced oxidative *** study was approved by the Institutional Animal Care and Use Committee(CE

关键词： antioxidants contrast sensitivity electroretinogram green tea neurodegeneration oxidative stress retinal degeneration retinitis pigmentosa systemic visual acuity

Effect of magnetic field orientation on fluidized beds of magnetic particles:Theory and experiment

在线全文

学校读者我要写书评

暂无评论

Particuology 2014年第1期12卷 54-63页

作者： Miguel ángel sánchez Quintanilla Manuel Jesús Espin José Manuel Valverde Department of Electronics and Electromagnetism University of Seville Department of Applied PhysicsⅡ University of Seville

Geldart-A fluidized beds of fine particles experience a jamming transition between a fluid-like state and a solid-like state at a certain superficial gas velocity, that depends on the relative strength of interparticle attractive forces with respect to particle weight, lnterparticle forces provide the bed with a certain tensile strength in the jammed state. In the work presented here we analyze the behavior of a fluidized bed of magnetic particles subjected to an externally applied magnetic field, which contributes to enhance interparticle forces. The importance of the magnetic contribution to interparticle forces is measured by the changes in the tensile strength and the superficial gas velocity at the jamming transition. The link of the field orientation with the microstructure of the bed is discussed,

关键词： Magneto-fluidization Jamming transition Fluidization Fine powders Cohesion Magnetization

Bidirectional relationship between gastrointestinal cancer and depression: The key is in the microbiota-gut-brain axis

在线全文

学校读者我要写书评

暂无评论

World Journal of Gastroenterology 2024年第48期30卷 5104-5110页

作者： Bryan Adrian Priego-Parra jose maria Remes-Troche Digestive Physiology and Gastrointestinal Motility Laboratory Instituto de Investigaciones Médico-BiológicasUniversidad VeracruzanaVeracruz 91700Mexico

In this Editorial,we review the recent publication in the World Journal of Gastroen-terology,which explores the complex relationship between depression and gastric cancer and offers *** topics discussed include the microbiota-gut-brain axis,dysbiosis,and the influence of microbial metabolites in ***,we address toxic stress caused by hypothalamic-pituitary-adrenal axis dysregulation,psychological assessments,and future research *** Editorial aims to expand the understanding of the bidirectional relationship between depression and gastrointestinal cancer.

关键词： Gastric cancer Depression Psychogastroenterology Microbiota-gut-brain axis Mood disorders Dysbiosis

selective intestinal decontamination for the prevention of early bacterial infections after liver transplantation

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

World Journal of Gastroenterology 2016年第26期22卷 5950-5957页

作者： Elena Resino Rafael san-Juan jose maria Aguado Unit of Infectious Diseases 12 de Octubre University Hospital

Bacterial infection in the first month after liver transplantation is a frequent complication that poses a serious risk for liver transplant recipients as contributes substantially to increased length of hospitalization and hospital costs being a leading cause of death in this period. Most of these infections are caused by gramnegative bacilli, although gram-positive infections, especially Enterococcus sp. constitute an emerging infectious problem. This high rate of early postoperative infections after liver transplant has generated interest in exploring various prophylactic approaches to surmount this problem. One of these approaches is selective intestinal decontamination(sID). sID is a prophylactic strategy that consists of the administration of antimicrobials with limited anaerobicidal activity in order to reduce the burden of aerobic gram-negative bacteria and/or yeast in the intestinal tract and so prevent infections caused by these organisms. The majority of studies carried out to date have found sID to be effective in the reduction of gram-negative infection, but the effect on overall infection is limited due to a higher number of infection episodes by pathogenic enterococci and coagulase-negative staphylococci. However, difficulties in general extrapolation of the favorable results obtained in specific studies together with the potential risk of selection of multirresistant microorganisms has conditioned controversy about the routinely application of these strategies in liver transplant recipients.

关键词： selective intestinal decontamination Liver transplant Infection Gram-negative bacterial infection Gram-positive bacterial infection Multirresistant

stochastic Models to Mitigate sparse sensor Attacks in Continuous-Time Non-Linear Cyber-Physical systems

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Computers, Materials & Continua 2023年第9期76卷 3189-3218页

作者： Borja Bordel sánchez Ramón Alcarria Tomás Robles Information Technologies Department Universidad Politécnica de MadridMadrid28031Spain Geospatial Information Department Universidad Politécnica de MadridMadrid28031Spain

Cyber-Physical systems are very vulnerable to sparse sensor *** current protection mechanisms employ linear and deterministic models which cannot detect attacks ***,in this paper,we propose a new non-linear generalized model to describe Cyber-Physical *** model includes unknown multivariable discrete and continuous-time functions and different multiplicative noises to represent the evolution of physical processes and randomeffects in the physical and ***,the digitalization stage in hardware devices is represented *** and most critical sparse sensor attacks are described through a stochastic *** reconstruction and protectionmechanisms are based on aweighted *** probability in data samples is estimated through different indicators commonly employed in non-linear dynamics(such as the Fourier transform,first-return maps,or the probability density function).A decision algorithm calculates the final reconstructed value considering the previous error *** experimental validation based on simulation tools and real deployments is also carried ***,the new technology performance and scalability are *** prove that the proposed solution protects Cyber-Physical systems against up to 92%of attacks and perturbations,with a computational delay below 2.5 *** proposed model shows a linear complexity,as recursive or iterative structures are not employed,just algebraic and probabilistic *** conclusion,the new model and reconstructionmechanism can protect successfully Cyber-Physical systems against sparse sensor attacks,even in dense or pervasive deployments and scenarios.

关键词： Cyber-physical systems sparse sensor attack non-linear models stochastic models security

Water-Based Processing of Fiberboard of Acrylic Resin Composites Reinforced With Cellulose Wood Pulp and Cellulose Nanofibrils

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Renewable Materials 2019年第5期7卷 403-413页

作者： Emanoele maria santos Chiromito Eliane Trovatti Antonio jose Felix Carvalho Department of Materials Engineering São Carlos School of EngineeringUniversity of São PauloAv.João Dagnone110013563-120São Carlos-SP-Brazil University of Araraquara-UNIARA R.Carlos Gomes1217CEP 14801-320AraraquaraSPBrazil

Despite the great potential of cellulose wood pulp and cellulose nanofibrils as reinforcing filler in thermoplastics,its use is limited due to its tendency to form agglomerates and due to its high hydrophilic *** we describe fiberboard composites with high contents of wood pulp or cellulose nanofibrils,and a resin of poly(styrene-methyl-methacrylate-acrylic acid)used as water-based *** wood pulp and cellulose nanofibrils were used directly in the form of water *** method is based on the flocculation of the polymer emulsion followed by agglomeration of a mixture of the polymer emulsion and cellulose suspension,leading to the co-precipitation of the composite material,which can be easily separated from the water *** with acrylic polymer/cellulose fibers in the proportions of 75:25,50:50 and 25:75 wt%were *** were characterized by scanning electron microscopy(sEM),Fourier transform infrared spectroscopy(FTIR),thermogravimetric analysis(TGA),dynamic mechanical analysis(DMA)and water absorption *** analysis revealed a very good dispersion of the fibers without evidence of agglomeration,which led to superior mechanical *** results showed the effectiveness of the methodology and the potential of cellulose wood pulp and CNF as reinforcement fillers in fiberboard composites and any other high fiber-content materials.

关键词： Cellulose wood pulp cellulose nanofibrils composites acrylic resin emulsion fiberboard

A Probabilistic Trust Model and Control Algorithm to Protect 6G Networks against Malicious Data Injection Attacks in Edge Computing Environments

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Computer Modeling in Engineering & sciences 2024年第10期141卷 631-654页

作者： Borja Bordel sánchez Ramón Alcarria Tomás Robles Department of Computer systems Universidad Politécnica de MadridMadrid28031Spain Department of Geospatial Engineering Universidad Politécnica de MadridMadrid28031Spain

Future 6G communications are envisioned to enable a large catalogue of pioneering *** will range from networked Cyber-Physical systems to edge computing devices,establishing real-time feedback control loops critical for managing Industry 5.0 deployments,digital agriculture systems,and essential *** provision of extensive machine-type communications through 6G will render many of these innovative systems autonomous and *** full automation will enhance industrial efficiency significantly,it concurrently introduces new cyber risks and *** particular,unattended systems are highly susceptible to trust issues:malicious nodes and false information can be easily introduced into control ***,Denialof-service attacks can be executed by inundating the network with valueless *** anomaly detection schemes require the entire transformation of the control software to integrate new steps and can only mitigate anomalies that conform to predefined mathematical *** based on an exhaustive data collection to detect anomalies are precise but extremely *** models,with their limited understanding of mobile networks,can achieve precision rates no higher than 75%.Therefore,more general and transversal protection mechanisms are needed to detect malicious behaviors *** paper introduces a probabilistic trust model and control algorithm designed to address this *** model determines the probability of any node to be *** channels are pruned for those nodes whose probability is below a given *** trust control algorithmcomprises three primary phases,which feed themodel with three different probabilities,which are weighted and ***,anomalous nodes are identified using Gaussian mixture models and clustering ***,traffic patterns are studied using digital Bessel functions and the functional scalar ***,the in

关键词： 6G networks noise injection attacks Gaussian mixture model Bessel function traffic filter Volterra filter

Abscisic Acid, High-Light, and Oxidative stress Down-Regulate a Photosynthetic Gene via a Promoter Motif Not Involved in Phytochrome- Mediated Transcriptional Regulation

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Molecular Plant 2008年第1期1卷 75-83页

作者： Roberto J. staneloni maria jose Rodriguez-Batiller Jorge J. Casal Fundacion Instituto Leloir and IIBBA-CONICET C1405BWE-Buenos Aires Argentina IFEVA Facultad de Agronomia Universidad de Buenos Aires and CONICET 1417 Buenos Aires Argentina

In etiolated seedlings, light perceived by phytochrome promotes the expression of light-harvesting chlorophyll a/b protein of photosystem Ⅱ （Lhcb） genes. However, excess of photosynthetically active radiation can reduce Lhcb expression. Here, we investigate the convergence and divergence of phytochrome, high-light stress and abscisic acid （ABA） signaling, which could connect these processes. Etiolated Arabidopsis thaliana seedlings bearing an Lhcb promoter fused to a reporter were exposed to continuous far-red light to activate phytochrome and not photosynthesis, and treated with ABA. We identified a cis-acting region of the promoter required for down-regulation by ABA. This region contains a CCAC sequence recently found to be necessary for ABI4-binding to an Lhcb promoter. However, we did not find a G-box-binding core motif often associated with the ABI4-binding site in genes promoted by light and repressed by ABI4. Mutations involving this motif also impaired the responses to reduced water potential, the response to high photosynthetic light and the response to methyl viologen but not the response to low temperature or to Norflurazon. We propose a model based on current and previous findings, in which hydrogen peroxide produced in the chloroplasts under high light conditions inter- acts with the ABA signaling network to regulate Lhcb expression. since the mutation that affects high-light and methyl viologen responses does not affect phytochrome-mediated responses, the regulation by retrograde and phytochrome signaling can finally be separated at the target promoter level.

关键词： .cis-Acting Abscisic ABA signaling High-Light and Oxidative Lhcb expression high-light stress Lhcb promoter